Method and apparatus for separating a solution

ABSTRACT

A method and apparatus for separating a solution containing a target substance. The solution is atomized into a mist in an atomizer ( 1 ) to produce a mixed fluid of mist and gas. In the collection of the mist from this mixed fluid, a gas transmission membrane ( 51 ) is used. The gas transmission membrane has a pore size that transmits gas but does not transmit the target substance contained in the mist. The mixed fluid is brought into contact with the primary surface of the gas transmission membrane ( 51 ), and the pressure on the primary surface is made higher than the pressure on the secondary surface of the opposite side. Thus, the gas in the mixed fluid is allowed to pass through the gas transmission membrane ( 51 ) to separate part or all of the gas contained in the mixed fluid.

This is a continuation-in-part (CIP) application of Ser. No. 11/091,486,filed Mar. 29, 2005 now U.S. Pat. No. 7,357,334.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method and an apparatus forseparating a solution that separate a higher concentration of alcoholmainly from an alcohol solution such as sake (Japanese rice wine) orsake raw materials.

2. Description of the Related Art

The inventors of the present invention have developed an apparatus forseparating alcohol which is a target material exhibiting a property ofsurface excess (See JP-A-2001-314724).

With this type of separating apparatus, an ultrasonic atomizationchamber with a closed structure is filled with an alcohol solution, andthe alcohol solution in the ultrasonic atomization chamber is atomizedinto a mist by means of ultrasonic oscillation with an ultrasonicoscillator. The separating apparatus aggregates and collects theatomized mist, and separates a higher concentration of alcohol solution.More specifically, the separating apparatus separates a higherconcentration of alcohol solution as a target material in the followingoperation.

With alcohol, which quickly moves to the surface and exhibits a propertyof surface excess, the concentration of alcohol is high at the surface.When the solution is oscillated in this state by ultrasonic oscillation,fine liquid droplets are ejected into air as a mist from the surface ofthe solution by ultrasonic oscillation energy. The mist ejected into theair has a higher concentration of alcohol. The reason is that thesolution at its surface with a higher concentration of alcohol isejected as the mist. Therefore, a solution with a higher concentrationof alcohol can be separated by aggregating and collecting the mist. Withthis method, a high concentration of alcohol solution can be separatedwithout heating the solution. Thus, a target material can be separatedat a high concentration. Furthermore, since heating is not necessary,the separating apparatus has an advantage in that the target materialcan be separated without deterioration in quality.

SUMMARY OF THE INVENTION

With the above-described apparatus, the solution is atomized into a mistinto circulated air. The reason why the air is circulated is that themist contained in the air and the target material vaporized from themist cannot be completely collected. That is to say, when the aircontaining an uncollectable portion of the target material is dischargedto the outside, the target material will disappear to increase the loss,so that the air is circulated into the ultrasonic atomization chamberwithout discharging the air to the outside. For this reason, theultrasonic atomization chamber is not supplied with fresh air, and theair containing the target material is circulated. Meanwhile, when asolution is to be atomized into a mist having a high concentration, theefficiency in producing a mist of the target material decreases if theair contains the target material. In atomizing the target material intoa mist, the mist of the target material can be produced efficiently byincreasing the extent of nonequilibrium between the solution surface andthe gas phase side. However, when the air in the ultrasonic atomizationchamber contains a high concentration of alcohol, the alcohol will be ina near equilibrium state between the solution surface and the gas phaseside, so that the mist of alcohol cannot be produced with goodefficiency.

The reason why the air from which the target material such as alcoholhas been collected is circulated into the ultrasonic atomization chamberis that the air contains the target material. Therefore, the aircirculated into the ultrasonic atomization chamber contains the targetmaterial such as alcohol, and this aggravates the efficiency ofatomizing the target material into a mist. This problem can be solved bycompletely collecting the target material before circulating the airinto the ultrasonic atomization chamber. However, in actual cases, thetarget material contained in the air cannot be completely collected, sothat the target material contained in the circulated air aggravates theefficiency in producing a mist.

Also, with a conventional apparatus, the air is cooled for aggregatingand collecting the mist. For this reason, the cooled air is circulatedinto the ultrasonic atomization chamber. However, in atomizing thesolution into a mist in the ultrasonic atomization chamber, theefficiency of producing a mist decreases when the temperature of thesolution is low. This problem can be solved by heating the solution.However, heating the solution requires heat energy. This increases thetotal energy consumption, and increases the energy consumption forconcentrating the solution.

Further, with a conventional apparatus, the air is cooled to aggregatethe mist, and this increases energy consumption. In particular, sincethe air serving as a carrier gas for carrying the mist is cooled toaggregate the mist, the amount of air to be cooled increases when theconcentration of the mist contained in the air decreases, and a largeamount of energy is consumed for cooling the air. In order to produce amist in the ultrasonic atomization chamber with good efficiency, theconcentration of the mist relative to the air must be lowered asdescribed before. However, when the concentration of the mist relativeto the air decreases, the energy for cooling the air increases. When theamount of mist relative to air is increased in order to avoid thisdrawback, the mist cannot be produced at high efficiency in theultrasonic atomization chamber.

The present invention has been developed in order to solve theaforementioned problems in the conventional art. The major object of thepresent invention is to provide a method and an apparatus for separatinga solution in which the solution can be efficiently separated withreduced energy consumption for cooling and the like by efficientlycollecting the mist while efficiently producing the mist.

A method of separating a solution according to the first aspect of thepresent invention includes an atomization step of atomizing a solutioncontaining a target substance into a mist in an atomizer 1 to produce amixed fluid of mist and gas, and a collection step of collecting themist from the mixed fluid obtained in the atomization step. With thisseparation method, while a gas contains at least one of hydrogen andhelium, in the collection step, a gas transmission membrane 51 of a poresize is used that transmits gas but does not transmit the targetsubstance contained in the mist. With this separation method, the mixedfluid is brought into contact with a primary surface of the gastransmission membrane 51, and a pressure on the primary surface is madehigher than a pressure on a secondary surface of an opposite side,whereby the gas in the mixed fluid is let to pass through the gastransmission membrane 51 to separate part or all of the gas contained inthe mixed fluid.

The atomizer 1 can atomize the solution into the mist by ultrasonicoscillation. The atomizer 1 can atomize the solution into the mist byultrasonic oscillation at a frequency of 1 MHz or higher.

With a method of separating a solution according to the second aspect ofthe present invention, in the collection step, the mixed fluid fromwhich part of the gas has been separated by the gas transmissionmembrane 51 can be further cooled to aggregate and collect the mist.Further, with this separation method, the mixed fluid, from which themist has been separated by cooling and aggregation after part of the gasis separated by the gas transmission membrane 51, can be circulated andsupplied to the atomizer 1. Furthermore, with the separation method ofthe present invention, the gas separated from the mixed fluid by the gastransmission membrane 51 can be supplied to the atomizer 1.

An apparatus for separating a solution according to the first aspect ofthe present invention includes an atomization chamber 4 to which asolution containing a target substance is supplied, an atomizer 1 forscattering the solution in the atomization chamber 4 into gas as a mistto produce a mixed fluid of gas and the mist in the solution, and an gasseparator 50 connected to the atomization chamber 4 to separate gas fromthe mixed fluid. An inside of the gas separator 50 is partitioned by angas transmission membrane 51 of a pore size that transmits gas but doesnot transmit the target substance, so as to provide, in an insidethereof, a primary passageway 52 for passing the mixed fluid and asecondary gas-discharging passageway 53 for discharging gas. A forcedgas discharger 54 is connected to the secondary gas-dischargingpassageway 53 of the gas separator 50. With this separation apparatus,the forced gas discharger 54 discharges the gas in the secondarygas-discharging passageway 53 in a forced manner to make a pressure on aprimary surface of the gas transmission membrane 51 higher than apressure on a secondary surface of the gas transmission membrane 51 sothat the gas contained in the mixed fluid may be transmitted through thegas transmission membrane 51 to separate gas from the mixed fluid thatpasses through the primary passageway 52.

An apparatus for separating a solution according to the second aspect ofthe present invention includes an atomization chamber 4 to which asolution containing a target substance is supplied, an atomizer 1 forscattering the solution in the atomization chamber 4 into gas as a mistto produce a mixed fluid of gas and the mist in the solution, and an gasseparator 50 connected to the atomization chamber 4 to separate gas fromthe mixed fluid. An inside of the gas separator 50 is partitioned by angas transmission membrane 51 of a pore size that transmits gas but doesnot transmit the target substance, so as to provide, in an insidethereof, a primary passageway 52 for passing the mixed fluid and asecondary gas-discharging passageway 53 for discharging gas. Acompressor 55 for pressurizing and supplying the mixed fluid in theatomization chamber 4 is connected to the primary passageway 52 of thegas separator 50. With this separation apparatus, the compressor 55presses the mixed fluid in the atomization chamber 4 into the primarypassageway 52 to make a pressure on a primary surface of the gastransmission membrane 51 higher than a pressure on a secondary surfaceof the gas transmission membrane 51 so that the gas contained in themixed fluid may be transmitted through the gas transmission membrane 51to separate gas from the mixed fluid that passes through the primarypassageway 52.

The separation method and the separation apparatus described above havean advantage in that the solution can be efficiently separated withreduced energy consumption for cooling and the like by efficientlycollecting the mist while efficiently producing the mist. The reason isthat, with the separation method and the separation apparatus describedabove, the mixed fluid of gas and the mist of the solution containingthe target substance produced by the atomizer is brought into contactwith a primary surface of an gas transmission membrane of a pore sizethat transmits gas but does not transmit the target substance containedin the mist, and a pressure on the primary surface is made higher than apressure on a secondary surface of an opposite side, whereby the gas inthe mixed fluid is let to pass through the gas transmission membrane toseparate the gas contained in the mixed fluid. The mixed fluid fromwhich gas has been separated has a small content of gas, and containsthe target substance in a supersaturated state, so that a highconcentration of the target substance can be collected with an extremelygood efficiency.

The gas transmission membrane 51 can include a filter member obtained bycoating a surface of a ceramic with zeolite. The atomizer 1 can includean ultrasonic oscillator 2 for atomizing the solution into a mist byultrasonic oscillation and an ultrasonic power supply 3 connected to theultrasonic oscillator 2 to supply high-frequency electric power to theultrasonic oscillator 2 for ultrasonic oscillation.

With the separation apparatus of the present invention, the mist can becollected by connecting any one of a cyclone, a punched plate, ademistor, a chevron, a scrubber, a spray tower, and an electrostaticcollector to an outlet side or an inlet side of the gas separator 50.

With the separation apparatus of the present invention, a collectionchamber 5 for aggregating and collecting the mist from the mixed fluidcan be connected to an outlet side of the primary passageway 52 providedin the gas separator 50. In addition, with the separation apparatus ofthe present invention, a cooling heat exchanger 33 can be provided inthe collection chamber 5, and the mist can be aggregated and collectedby cooling the mixed fluid with the cooling heat exchanger 33.

With the separation apparatus of the present invention, a collectionchamber 5 can be connected to the atomization chamber 4, whereby the gasfrom which gas has been separated by the gas separator 50 and furtherthe mist has been separated in the collection chamber 5 can be suppliedto the atomization chamber 4. In addition, with the separation apparatusof the present invention, the secondary gas-discharging passageway 53 ofthe gas separator 50 can be connected to the atomization chamber 4,whereby the gas separated from the mixed fluid by the gas transmissionmembrane 51 of the gas separator 50 can be supplied to the atomizationchamber 4.

Further, with the separation method and the separation apparatus thataggregate and collect the mist by cooling the mixed fluid from whichpart of gas has been separated by the gas transmission membrane, thetarget substance can be efficiently collected with reduced amount ofenergy consumption for cooling. The reason is that the mixed fluid fromwhich gas has been separated by the gas transmission membrane has areduced amount of gas, so that, when cooling, the target substance canbe collected efficiently with reduced amount of cooling.

Furthermore, with the separation method and the separation apparatusthat circulate into the atomization chamber the mixed fluid from whichthe mist has been separated by being cooled and aggregated after part ofthe gas is separated by the gas transmission membrane, the mist can beefficiently produced while reducing the energy consumption. The reasonis that, since the mixed fluid with reduced amount of cooling iscirculated into the atomization chamber, the solution can be atomizedinto a mist while reducing the energy consumption for heating thesolution in the atomization chamber.

Further, the separation method and apparatus in which the gas separatedfrom the mixed fluid by the gas transmission membrane is supplied to theatomization chamber has an advantage in that the solution can beefficiently atomized into a mist in the atomization chamber. The reasonis that the gas separated from the mixed fluid does not contain thetarget substance. Also, since the gas separated from the mixed fluid bythe gas transmission membrane is gas controlled to have an optimumtemperature for producing the mist in the atomization chamber, the mistcan be efficiently produced by supplying this gas into the atomizationchamber.

The above and further objects and features of the invention will morefully be apparent from the following detailed description withaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram schematically showing an apparatus for concentratinga solution according to one embodiment of the present invention.

FIG. 2 is a diagram schematically showing an apparatus for concentratinga solution according to another embodiment of the present invention.

FIG. 3 is a diagram schematically showing an apparatus for concentratinga solution according to another embodiment of the present invention.

FIG. 4 is a diagram schematically showing an apparatus for concentratinga solution according to another embodiment of the present invention.

FIG. 5 is a cross-sectional view schematically showing one example of anultrasonic atomization chamber and an ultrasonic atomizer.

FIG. 6 is an enlarged cross-sectional view showing one example of aconnection structure between an ultrasonic oscillator and a detachableplate.

FIG. 7 is a plan view of the detachable plate shown in FIG. 6.

FIG. 8 is a cross-sectional view showing a state in which the detachableplate is attached to the ultrasonic atomization chamber.

FIG. 9 is an enlarged cross-sectional view showing a connectionstructure between the detachable plate and the ultrasonic atomizationchamber shown in FIG. 8.

FIG. 10 is an enlarged cross-sectional perspective view showing anotherexample of a connection structure between the ultrasonic oscillator andthe detachable plate.

FIG. 11 is an enlarged cross-sectional view showing another example of aconnection structure between the ultrasonic oscillator and thedetachable plate.

FIG. 12 is an enlarged cross-sectional view showing another example of aconnection structure between the ultrasonic oscillator and thedetachable plate.

FIG. 13 is a cross-sectional view showing another example of disposingthe detachable plate in the ultrasonic atomization chamber.

FIG. 14 is a graph showing an absolute ethanol amount in air underpressure.

FIG. 15 is a cross-sectional view schematically showing one example of acollection chamber.

FIG. 16 is a cross-sectional view schematically showing another exampleof a collection chamber.

FIG. 17 is a cross-sectional view schematically showing another exampleof a collection chamber.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

An apparatus for separating a solution according to the presentinvention atomizes a solution containing a target material, whichquickly moves to the liquid surface and exhibits a physical property ofsurface excess, into a mist and then separates the solution bycollecting the mist. In the present invention, solutes and solvents ofthe solution are not specifically limited. Though water is mainly usedas a solvent in the present invention, organic solvents such as alcoholcan be used other than water. Following solutions containing targetmaterials can be used, for example.

(1) Refined sake, beer, wine, vinegar, mirin (sweet sake for cooking),spirits, shochu (Japanese spirits), brandy, whisky and liqueur.

(2) Solutions containing a perfume such as pinene, linalool, limonene,or polyphenols, an aromatic component, or a fragrant component.

(3) Solutions containing an organic compound that is classified as anyone of alkane and cycloalkane, which are a saturated hydrocarbon,alkene, cycloalkene, and alkyne, which are an unsaturated hydrocarbon,ether, thioether, and aromatic hydrocarbon, or a compound obtained bybonding these.

(4) Solution containing a substance obtained by substituting ahalogen(s) for at least one hydrogen atom or functional group of anorganic compound that is classified as any one of alkane andcycloalkane, which are a saturated hydrocarbon, alkene, cycloalkene andalkyne, which are an unsaturated hydrocarbon, ether, thioether, andaromatic hydrocarbon, or a bonded compound of these.

(5) Solution containing a substance obtained by substituting a hydroxygroup(s) for at least one hydrogen atom or functional group of anorganic compound that is classified as any one of alkane andcycloalkane, which are a saturated hydrocarbon, alkene, cycloalkene andalkyne, which are an unsaturated hydrocarbon, ether, thioether, andaromatic hydrocarbon, or a bonded compound of these.

(6) Solution containing a substance obtained by substituting an aminogroup(s) for at least one hydrogen atom or functional group of anorganic compound that is classified as any one of alkane andcycloalkane, which are a saturated hydrocarbon, alkene, cycloalkene andalkyne, which are an unsaturated hydrocarbon, ether, thioether, andaromatic hydrocarbon, or a bonded compound of these.

(7) Solution containing a substance obtained by substituting a carbonylgroup(s) for at least one hydrogen atom or functional group of anorganic compound that is classified as any one of alkane andcycloalkane, which are a saturated hydrocarbon, alkene, cycloalkene andalkyne, which are an unsaturated hydrocarbon, ether, thioether, andaromatic hydrocarbon, or a bonded compound of these.

(8) Solution containing a substance obtained by substituting a carboxylgroup(s) for at least one hydrogen atom or functional group of anorganic compound that is classified as any one of alkane andcycloalkane, which are a saturated hydrocarbon, alkene, cycloalkene andalkyne, which are an unsaturated hydrocarbon, ether, thioether, andaromatic hydrocarbon, or a bonded compound of these.

(9) Solution containing a substance obtained by substituting a nitrogroup(s) for at least one hydrogen atom or functional group of anorganic compound that is classified as any one of alkane andcycloalkane, which are a saturated hydrocarbon, alkene, cycloalkene andalkyne, which are an unsaturated hydrocarbon, ether, thioether, andaromatic hydrocarbon, or a bonded compound of these.

(10) Solution containing a substance obtained by substituting a cyanogroup(s) for at least one hydrogen atom or functional group of anorganic compound that is classified as any one of alkane andcycloalkane, which are a saturated hydrocarbon, alkene, cycloalkene andalkyne, which are an unsaturated hydrocarbon, ether, thioether, andaromatic hydrocarbon, or a bonded compound of these.

(11) Solution containing a substance obtained by substituting a mercaptogroup(s) for at least one hydrogen atom or functional group of anorganic compound that is classified as any one of alkane andcycloalkane, which are a saturated hydrocarbon, alkene, cycloalkene andalkyne, which are an unsaturated hydrocarbon, ether, thioether, andaromatic hydrocarbon, or a bonded compound of these.

(12) Solutions containing a substance obtained by substituting a metalion(s) for at least one atom of the target substances mentioned in (3)to (11).

(13) Solutions containing a substance obtained by substituting anarbitrary molecule(s) of the molecules mentioned in (3) to (11) for anarbitrary hydrogen atom(s), carbon atom(s), or functional group(s)contained in the target substances mentioned in (3) to (11).

The target materials contained in the above solutions quickly move tothe surface and exhibit a physical property of surface excess. Theconcentrations of these target material are high at the surface. Whenthe solutions at the surface are atomized into a mist, the mist has ahigher concentration of the target materials. Therefore, aggregating andcollecting the mist can make the concentration of the target materialshigher. That is, a compound containing a higher concentration of thetarget material can be separated from the solution. Though the atomizerfor atomizing the solution at the surface into a mist is notspecifically limited, the atomizer that can be used may be one thatoscillates the solution at an ultrasonic frequency, one that dischargesthe solution from a capillary and electrostatically atomizes thesolution at the electrode, or the like.

The following description will describe an apparatus and a method forseparating a higher concentration of alcohol from a solution containingthe alcohol as a target material by producing a mist through ultrasonicoscillation. However, in the present invention, the target material isnot limited to an alcohol. Any target material, which quickly moves tothe surface and exhibits a physical property of surface excess, can beseparated. Also, the atomizer that atomizes a solution into a mist isnot limited to an atomizer by ultrasonic oscillation. For example, anelectrostatic atomizer or the like can be used.

The separation apparatus shown in FIGS. 1 to 4 includes an atomizationchamber 4, 204, 304, 404 having a closed structure to which a solutionis supplied, an atomizer 1, 201, 301, 401 for atomizing the solution inthe atomization chamber 4, 204, 304, 404 into a mist, an air separator50, 2050, 3050, 4050 for separating air from a mixed fluid of air andthe mist atomized in the atomization chamber 4, 204, 304, 404, acollection chamber 5, 205, 305, 405 for further aggregating andcollecting the mixed fluid from which part of the air has been separatedby the air separator 50, 2050, 3050, 4050, and a forced transporter 35,2035, 3035, 4035 for transporting the mixed fluid.

Further, in place of air, a gas containing either of hydrogen or heliumcan be used as a carrier gas. To be used as the carrier gas is a gasmade up with one of hydrogen and helium, a mixed gas of hydrogen andhelium, a mixed gas of hydrogen and air, a mixed gas of helium and air,or alternatively a mixed gas of hydrogen, helium and air. Thus, byusing, as the carrier gas, hydrogen or helium, or by using a mixed gasof hydrogen and helium, or by using a mixed gas of hydrogen or heliumand air, the oxygen concentration in the apparatus and in its vicinitycan be reduced to be proven useful for an explosion prevention as well.

The solution separating method and apparatus include the feature thatwhile maintaining an increased efficiency in atomizing the mist, themist can be collected efficiently and the highly condensed concentrationcan be efficiently made with a smaller amount of energy. In other words,the present invention is so designed that when the gas is a gascontaining at least one of hydrogen and helium, the solution can becondensed efficiently to a higher concentration for two reasons that theefficiency in atomizing into the mist is increased and that the gas isseparated more effectively from the mixed fluid by means of a gastransmission membrane. The efficiency in atomizing the solution into themist to be mixed with the gas is influenced by a molecular weight of thegas. The maximum amount of mist vaporization that can be contained in adry gas increases when the molecular weight of the gas is smaller. Forexample, the air used as a conventional gas has a molecular weight ofabout 29, while the molecular weight of hydrogen is 2 and the molecularweight of helium is 4, both of which are very small when compared withthe air. For this reason, in the case of hydrogen and helium, themaximum weight of mist vaporization that can be contained in 1 kg of drygas becomes very large when compared with the air. That is to say,hydrogen and helium can contain a large amount of solution in a state ofa gas. Such gas has very great efficiency in atomizing the solution intothe mist. Therefore, in the present invention, when the gas is a gasthat contains at least one of hydrogen and helium, the efficiency can beincreased in atomizing the solution into the mist. The mixed fluid canefficiently collect the mist by using the gas transmission membrane.This is because the mist can be collected by reducing the amount of gaswhich passes through the gas transmission membrane. Further, the gastransmission membrane allows hydrogen and helium more efficiently thanthe air. This is because hydrogen and helium are of a small size whencompared with the air, so as to be able to pass through the gastransmission membrane smooth enough. The molecular weight of gas is oneparameter in determining the size of a molecule, and hydrogen and heliumwith a smaller molecular weight than the airpasses through the gastransmission membrane more smoothly than the air. For this reason, thepresent invention, in which the gas is a gas that contains at least oneof hydrogen and helium, can efficiently separate the gas from the mixedfluid by means of the gas transmission membrane. In the mixed fluid fromwhich the gas has been separated by means of the gas transmissionmembrane, the target substance contained in the mist getsover-saturated, so that the target substance can be collected veryefficiently and in a high concentration. As described above, in thepresent invention, while the solution is efficiently atomized into themist, the mist can efficiently pass through the gas transmissionmembrane, and further the gas amount in the mixed fluid that isseparated by the gas transmission membrane can be made small, so thatthe overall efficient can be improved to a great extent.

The solution is supplied to the atomization chamber 404 by a pump 4010.The atomization chamber 4, 204, 304, 404 does not atomize all thesolution supplied thereto as a mist. The reason is that, if all thesolution is atomized and collected in the collection chamber 5, 205,305, 405, the concentration of a target material such as alcohol in thesolution collected in the collection chamber 5, 205, 305, 405 will bethe same as that of the solution supplied to the atomization chamber 4,204, 304, 404. With the solution supplied to the atomization chamber 4,204, 304, 404, the concentration of the target material decreases as theamount of the solution decreases due to the atomization into a mist.Therefore, the concentration of the target material contained in themist also gradually decreases. The solution in the atomization chamber4, 204, 304, 404 is replaced with a new solution when the concentrationof the target material decreases.

A solution containing the target material, for example, at aconcentration of 10 to 50% by weight is atomized in the atomizationchamber 4, 204, 304, 404. When the concentration of the target materialdecreases, the solution in the atomization chamber 4, 204, 304, 404 isreplaced with a new solution. The solution is replaced in a batchmanner, i.e. by a method in which the solution is replaced with a newone each time after a predetermined period of time passes. However, astock solution tank 4011 storing a solution may be connected to theatomization chamber 404 via a pump 4010, whereby the solution can besupplied continuously from the stock solution tank 4011. With thisapparatus, the atomization chamber 404 is supplied with a solution fromthe stock solution tank 4011 while discharging the solution in theatomization chamber 404, thus preventing decrease in the concentrationof the target material such as alcohol in the solution in theatomization chamber 404. Also, as shown by an arrow B in FIG. 4, thesolution in the atomization chamber 404 can be discharged to the outsidewithout being circulated into the stock solution tank 4011, so as toprevent decrease in the concentration of the target material containedin the stock solution tank 4011.

The solution in the atomization chamber 4, 204, 304, 404 is atomizedinto a mist by the atomizer 1, 201, 301, 401. The mist produced by theatomizer 1, 201, 301, 401 has a higher concentration of the targetmaterial than the solution. In this case, the atomizer 1, 201, 301, 401produces a mist from the solution by atomization, and the mist isaggregated and collected, whereby a highly concentrated solution can beefficiently separated.

The atomizer 1, 201, 301, 401 includes a plurality of ultrasonicoscillators 2, 202, 302, 402 and an ultrasonic power supply 3, 203, 303,403 that supplies high-frequency electric power to these ultrasonicoscillators 2, 202, 302, 402. The atomizer 1, 201, 301, 401 preferablyatomizes the solution by ultrasonic oscillation at a frequency of 1 MHzor higher. Use of this atomizer 1, 201, 301, 401 has an advantage inthat the solution can be atomized into a mist made of extremely finedroplets, and can concentrate the solution at a higher concentration. Inthe present invention, the atomizer is not limited to the one byultrasonic oscillation; however, with an atomizer by ultrasonicoscillation, the oscillation frequency can be made lower than 1 MHz.

The atomizer 1, 201, 301, 401 that oscillates the solution at anultrasonic frequency scatters the solution from the solution surface Was a mist with a concentration higher than the solution in theatomization chamber 4, 204, 304, 404. When the solution is subjected toultrasonic oscillation, liquid columns P appear on the solution surfaceW. The mist is produced from the surface of the liquid columns P. Withthe atomizer 81 shown in FIG. 5, ultrasonic oscillators 82 of theatomizer 81 are arranged to face upwards on the bottom of theatomization chamber 84 filled with the solution. The ultrasonicoscillators 82 emit ultrasonic waves upward from the bottom toward thesolution surface W, and subject the solution surface W to ultrasonicoscillation to produce liquid columns P. The ultrasonic oscillators 82emit ultrasonic waves in the vertical direction.

The atomizer 81 shown in the drawings includes a plurality of ultrasonicoscillators 82 and an ultrasonic power supply 83 that oscillates theseultrasonic oscillators 82 at an ultrasonic frequency. The ultrasonicoscillators 82 are fixed, in a watertight structure, to the bottom ofthe atomization chamber 84. The apparatus, which oscillates the solutionat an ultrasonic frequency by means of the plurality of ultrasonicoscillators 82, produces a mist from the solution more efficiently.

The plurality of ultrasonic oscillators 82 are fixed to a detachableplate 812 in a watertight structure, as shown in FIGS. 6 and 7. Thedetachable plate 812, on which the plurality of ultrasonic oscillators82 are fixed, is attached to a casing 813 of the atomization chamber 84to be capable of being attached and detached in a watertight structure,as shown in FIGS. 8 and 9. The detachable plate 812 is attached to thecasing 813 of the atomization chamber 84, thus, each ultrasonicoscillator 82 oscillates the solution in the atomization chamber 84 atan ultrasonic frequency.

The detachable plate 812 shown in FIGS. 6 and 7 includes a front sideplate 812A and a backside plate 812B. The front side plate 812A and thebackside plate 812B are laminated to sandwich the ultrasonic oscillators82 between the front side plate 812A and the backside plate 812B in awatertight structure. The front side plate 812A is provided with throughholes 812 a opening thereon. The front side plate 812A and the backsideplate 812B sandwich and fix the ultrasonic oscillators 82 so thatoscillation surfaces 82A are positioned in the through holes 812 a. Thebackside plate 812B is provided with recessed portions 812 b in whichthe ultrasonic oscillators 82 are fitted. With the detachable plate 812of FIG. 6, the recessed portions 812 b are provided in the backsideplate 812B; however, the recessed portions may be provided in the frontside plate to fit the ultrasonic oscillators in the recessed portions.Here, in FIG. 6, reference numeral 812 c represents through holes, andreference numeral 819 represents a lead wire.

In order to provide a watertight structure between the ultrasonicoscillators 82 and the front side plate 812A, a packing member 816 issandwiched between the ultrasonic oscillators 82 and the front sideplate 812A. With the atomizer 81 shown in FIG. 6, another packing member816 is also sandwiched between the ultrasonic oscillators 82 and thebackside plate 812B in order to provide a watertight structure. However,with the atomizer, the watertight structure need not always be providedbetween the ultrasonic oscillators and the backside plate. The reason isthat, when a detachable plate provides a watertight structure betweenthe ultrasonic oscillators and the front side plate, fixing thedetachable plate on the lower surface of the casing of the atomizationchamber can prevent leakage of the solution in the atomization chamber.The packing member 816 is an O-ring made of elastic rubber. The packingmember 816 of the O-ring is disposed on the outer periphery of theoscillation surface 82A of the ultrasonic oscillators 82 and a surfaceof the front side plate 812A opposed thereto. The packing member 816provides a watertight structure between the oscillation surface 82A ofthe ultrasonic oscillators 82 and the front side plate 812A, therebypreventing leakage of water from there. Additionally, the outerperiphery of the ultrasonic oscillators 82 and the backside plate 812Bare connected in a watertight structure.

The packing member 816 is an elastic rubber made of Teflon (registeredtrademark), silicone, natural or synthetic rubber, or the like. Thepacking members 816 are sandwiched between the ultrasonic oscillators 82and the front side plate 812A and between the ultrasonic oscillators 82and the backside plate 812B so as to be elastically deformed andcrushed. Thus, the packing members 816 come into close contact with thesurfaces of the ultrasonic oscillators 82, the front side plate 812A,and the backside plate 812B without a gap so as to provide a watertightstructure in the connection portions. Here, the packing member 816 maybe a ring-shaped metal packing member made of a metal such as copper,brass, aluminum, or stainless steel.

With the detachable plate 812 shown in FIGS. 6 and 7, the front sideplate 812A and the backside plate 812B are connected to each other by ahinge 817 at one end of each plate. The front side plate 812A and thebackside plate 812B of the detachable plate 812 can be opened to attachand detach the ultrasonic oscillators 82 easily. When the ultrasonicoscillators 82 are to be replaced, the front side plate 812A and thebackside plate 812B are opened. In this state, the old ultrasonicoscillators are removed, and then new ultrasonic oscillators 82 andpacking members 816 are put into predetermined positions. Subsequently,the front side plate 812A and the backside plate 812B are closed, thus,replacement of ultrasonic oscillators 82 is achieved. In addition, theclosed backside plate 812B and front side plate 812A are connected at anend of each plate opposite to the hinge 817 with a fastening screw (notshown), or alternatively connected by being fastened to the casing 813of the atomization chamber 84.

The above atomizer 81 provides a watertight structure by means of thepacking member 816; however, the atomizer may provide a watertightstructure by filling the positions corresponding to the packing memberwith a caulking material. Furthermore, with the atomizer 81 shown inFIG. 6, the detachable plate 812 is composed of two metal plates or hardnon-metal plates of the front side plate 812A and the backside plate812B; however, the detachable plate 812 may be composed of one plate asshown in FIGS. 10 to 12. The detachable plates 1012, 1112, and 1212 aremetal plates or hard non-metal plates. The detachable plates 1012, 1112,and 1212 are provided with recessed portions 1012 b, 1112 b thereon orprovided with opened through holes 1212 a for disposing ultrasonicoscillators 102, 112, 122.

With the atomizer 101 of FIG. 10, the ultrasonic oscillator 102 isdisposed in the recessed portion 1012 b of the detachable plate 1012,and packing members 1016 are arranged on the upper and lower peripheriesof the ultrasonic oscillator 102. Furthermore, a ring plate 1018 isfixed to an opening of the detachable plate 1012. The ring plate 1018presses the packing member 1016 disposed on the upper surface of theultrasonic oscillator 102, thus the ultrasonic oscillator 102 is fixedin the recessed portion 1012 b in a watertight structure. The recessedportion 1012 b is provided with a through hole 1012 c on its bottom. Alead wire 1019 extends outward through the through hole 1012 c. Here, inFIG. 10, reference numeral 1012A represents an oscillation surface.

With the atomizer 111 of FIG. 11, the ultrasonic oscillator 112, whichis put into the recessed portion 1112 b of the detachable plate 1112, isbonded with a caulking material 1120 and fixed to form a watertightstructure without using the packing member and the ring plate. With thisultrasonic oscillator 112, a lead wire 1119 extends outward through apenetrating through hole 1112 c that is open at the bottom of therecessed portion 1112 b. The through hole 1112 c, through which the leadwire 1119 passes, is filled with the caulking material 1120, thusproviding a watertight structure that prevents leakage of water. Here,in FIG. 11, reference numeral 112A represents an oscillation surface.

With the atomizer 121 of FIG. 12, the detachable plate 1212 is providedwith a penetrating through hole 1212 a. The ultrasonic oscillator 122 isfixed to the lower surface of the detachable plate 1212 so that anoscillation surface 122A is positioned under the through hole 1212 a. Inorder to fix the ultrasonic oscillator 122 to the detachable plate 1212,a fixing member 1221 is fixed to the bottom surface of the detachableplate 1212. The ultrasonic oscillator 122 is fixed, in a watertightstructure, to the detachable plate 1212 via packing members 1216arranged on the upper and lower peripheries of the ultrasonic oscillator122. The fixing member 1221 is a stepped annular member, which has arecessed portion and an outer flange portion, and is fixed to thedetachable plate 1212 by screwing fixing screws 1222, which penetratethrough the outer flange portion, in the detachable plate 1212. Thefixing member 1221 presses the packing member 1216 disposed on the lowersurface of the ultrasonic oscillator 122 by the bottom of the recessedportion, thus the ultrasonic oscillator 122 is fixed to the detachableplate 1212 in a watertight structure. The fixing member 1221 is providedwith a through hole 1221A on the bottom of the recessed portion. A leadwire 1219 extends outward through the through hole 1221A.

FIGS. 8 and 9 are views of the atomizer 81 fixed to the atomizationchamber 84. The atomization chamber 84 shown in these figures isprovided with openings 813A on the bottom surface of the casing 813. Thedetachable plate 812 is fixed so that the openings 813A are closed in awatertight structure. The detachable plate 812 is fixed, in a watertightstructure, to the casing 813 via a packing member 823. Metal fixingmembers 824 are fixed to the bottom surface of the casing 813 in orderto fix the detachable plate 812 thereto. The metal fixing members 824are shaped in an L-shape. Fastening screws 825, which penetrate throughthe fixing members 824, press and fix the detachable plate 812 to thecasing 813 of the atomization chamber 84. The plurality of ultrasonicoscillators 82, which are fixed to the atomization chamber 84 in thisstructure, oscillate the solution upward from the bottom surface of thecasing 813 to the upper surface at an ultrasonic frequency. Thedetachable plate 812 is detachably mounted to the bottom surface of thecasing 813 of the atomization chamber 84 so as to close the openings813A.

A detachable plate may be immersed in the solution in an atomizationchamber 134 to oscillate the solution at ultrasonic frequency, as shownin FIG. 13. This structure facilitates placement of a detachable plate1312 to the atomization chamber 134 in a detachable manner. With anatomizer 131 that is immersed in the solution, the ultrasonic oscillatoris fixed in a watertight structure to the detachable plate 1312 exceptthe oscillation surface thereof as a structure shown, for example, inFIG. 11. Here, in FIG. 13, the reference numeral 133 represents anultrasonic power supply.

If the ultrasonic oscillator 2, 202, 302, 402 or the ultrasonic powersupply 3 heats the solution in the atomization chamber 4, 204, 304, 404to a high temperature, the quality may deteriorate. Forced cooling ofthe ultrasonic oscillator 2, 202, 302, 402 can solve this problem.Furthermore, the ultrasonic power supply 3, 203, 303, 403 is preferablyalso cooled. The ultrasonic power supply 3, 203, 303, 403 does notdirectly heat the solution, but heats the surroundings thereof tothereby heat the solution indirectly. The ultrasonic oscillator 2, 202,302, 402 and the ultrasonic power supply 3 can be cooled by disposing acooling pipe in a thermally coupled state, namely by disposing a coolingpipe in a state of being in contact. The cooling pipe cools theultrasonic oscillator and the ultrasonic power supply by running aliquid or refrigerant, which is cooled by a cooler, or cooling watersuch as ground water or service water.

Furthermore, the separation apparatus shown in FIG. 4 includes atemperature control mechanism 4075 for controlling the temperature ofthe solution in the atomization chamber 404. The temperature controlmechanism 4075 includes a cooler 4076 for cooling the solution so thatthe temperature of the solution will be a predetermined temperature.This temperature control mechanism 4075 senses the temperature of thesolution stored in the atomization chamber 404 by means of a temperaturesensor 4077, and controls the cooler 4076 so as to maintain thetemperature of the solution to be not higher than 30° C. Thus, theseparation apparatus, which controls the temperature of the solution bymeans of the temperature control mechanism 4075, can increase thesolubility of bubbles supplied from the bubble generator 4028.

The temperature of the solution affects the efficiency in atomizing thesolution into a mist by means of ultrasonic oscillation. When thetemperature of the solution lowers, the efficiency in atomizing thesolution into a mist decreases. When the temperature of the solution islowered, the deterioration of the product quality will be smaller.However, if the temperature of the solution is low, the efficiency inatomizing the solution into a mist decreases, so that the temperature ofthe solution is set at a temperature at which the solution can beefficiently atomized into a mist while considering the property of thetarget substance that changes with temperature. A target substance thatdoes not deteriorate in product quality or does not raise a problem evenat a high temperature can be efficiently atomized into a mist by raisingthe temperature of the solution.

Further, with the separation apparatus shown in FIG. 4, air is blownfrom a blower mechanism 4027 to a liquid column P produced at thesolution surface W by ultrasonic oscillation in the atomization chamber404. The blower mechanism 4027 shown in this figure is provided with afan 4029 for blowing air to the liquid column P. Thus, the separationapparatus that blows air to the liquid column P with the blowermechanism 4027 has an advantage in that the solution can be efficientlyatomized into a mist from the surface of the liquid column P. However,the separation apparatus of the present invention need not always beprovided with a blower mechanism to blow air to the liquid column, asshown in FIGS. 1 to 3.

The air separator 50, 2050, 3050, 4050 separates air from the mixedfluid supplied from the atomization chamber 4. An inside of this airseparator 50, 2050, 3050, 4050 is partitioned into a primary passageway52, 2052, 3052, 4052 and a secondary air-discharging passageway 53,2053, 3053, 4053 with an air transmission membrane 51, 2051, 3051, 4051.The primary passageway 52, 2052, 3052, 4052 is connected to the atomizer1, 201, 301, 401 to pass the mixed fluid. The secondary air-dischargingpassageway 53, 2053, 3053, 4053 discharges the air that is separatedfrom the mixed fluid by being passed through the air transmissionmembrane 51, 2051, 3051, 4051.

The air transmission membrane 51, 2051, 3051, 4051 passes only air anddoes not pass the target substance. Therefore, this air transmissionmembrane 51, 2051, 3051, 4051 to be used here is a molecular sieve whichis a membrane of a pore size that transmits air but does not transmitthe target substance. Air is made of about 80% nitrogen and 20% oxygen.Therefore, the air transmission membrane 51, 2051, 3051, 4051 is amembrane of a pore size that transmits nitrogen and oxygen. The poresize of this air transmission membrane 51, 2051, 3051, 4051 ispreferably 0.4 nm to 0.5 nm. This air transmission membrane 51, 2051,3051, 4051 transmits the air made of nitrogen and oxygen, which aresmaller than the pore size, but does not transmit the target substancesuch as ethanol, which is larger than a pore size. The above airtransmission membrane 51, 2051, 3051, 4051 is fabricated, for example,by coating a surface of a ceramic with zeolite.

The primary passageway 52, 2052, 3052, 4052 of the air separator 50,2050, 3050, 4050 is connected to the atomization chamber 4, 204, 304,404 to bring the mixed fluid into contact with the primary surface ofthe air transmission membrane 51, 2051, 3051, 4051. Further, with theapparatus of FIGS. 1, 3, and 4, the secondary air-discharging passageway53, 3053, 4053 is connected to a forced air discharger 54, 3054, 4054and, with the apparatus of FIG. 2, the primary passageway 2052 isconnected to a compressor 2055, so as to make the pressure on theprimary surface higher than the pressure on the secondary surfaceopposite thereto. Thus, the air in the mixed fluid is transmittedthrough the air transmission membrane 51, 2051, 3051, 4051 to separatepart or all of the air in the mixed fluid.

The gas transmission membrane 7 allows the carrier gas alone to passthrough, but not the target substance. Therefore, this carrier gastransmission membrane 7 uses a molecular sieve with a membrane of such apore size as may allow the carrier gas to pass through but not thetarget substance. In the apparatus in which alcohol is condensed as atarget substance, the pore size of the carrier gas transmission membrane7 is preferably 0.4-0.5 nm. The carrier gas transmission membrane 7 doesnot allow a target substance, such as ethanol which is larger than thepore size, to pass through, but the membrane 7 allows hydrogen, helium,or a carrier gas made up with a gas containing at least one of hydrogenand helium, which is all smaller than the pore size, to pass through.The carrier gas transmission membrane 7 with the above-described size ismade by coating zeolite on the surface of ceramic.

The forced air discharger 54, 3054, 4054 is a suction pump such as avacuum pump that sucks and discharges air in a forced manner. Thesuction side of the forced air discharger 54, 3054, 4054 is connected tothe secondary air-discharging passageway 53, 3053, 4053 to discharge theair in the secondary air-discharging passageway 53, 3053, 4053 forcibly.The secondary air-discharging passageway 53, 3053, 4053 from which airis discharged will have a pressure lower than an atmospheric pressure,and hence will have a lower pressure than the primary passageway 52,3052, 4052. In other words, the pressure in the primary passageway 52,3052, 4052 will be relatively higher than the pressure in the secondaryair-discharging passageway 53, 3053, 4053. When the system is broughtinto this state, the air contained in the mixed fluid is transmittedthrough the air transmission membrane 51, 3051, 4051 to pass from theprimary passageway 52, 3052, 4052 to the secondary air-dischargingpassageway 53, 3053, 4053 to thereby be separated from the mixed fluid.

With the apparatus of FIG. 2, the compressor 2055 presses the mixedfluid into the primary passageway 2052. The suction side of thecompressor 2055 is connected to the atomization chamber 204. Thesecondary air-discharging passageway 2053 is open to ambient atmosphere.However, a forced air discharger may be connected to the secondaryair-discharging passageway to reduce the pressure of the secondaryair-discharging passageway to be equal to or lower than an atmosphericpressure. The compressor 2055 pressurizes the mixed fluid to have apressure equal to or higher than atmospheric pressure, and presses themixed fluid into the primary passageway 2052, whereby the pressure inthe primary passageway 2052 is made higher than the pressure in thesecondary air-discharging passageway 2053. In this state, the aircontained in the mixed fluid is transmitted through the air transmissionmembrane 2051 by a pressure difference between the primary surface andthe secondary surface. The air transmitted through the air transmissionmembrane 2051 is transported from the primary passageway 2052 to thesecondary air-discharging passageway 2053 to thereby be separated fromthe mixed fluid. This structure can increase the pressure differencebetween the primary surface and the secondary surface of the airtransmission membrane 2051. For this reason, the air in the mixed fluidcan be speedily separated. The reason is that the compressor 2055 canpress the mixed fluid into the primary passageway 2052 by a highpressure.

Further, with the apparatus of FIG. 2, the suction side of thecompressor 2055 is connected to the atomization chamber 204 via aprevious-stage collection chamber 2060. With the separation apparatus,any one of a cyclone, a punched plate, a demistor, a chevron, ascrubber, a spray tower, and an electrostatic collector can be connectedas the previous-stage collection chamber 2060 to collect the mist. Withthe separation apparatus of FIG. 2, the mechanism such as these isdisposed between the air separator 2050 and the atomization chamber 204to serve as the previous-stage collection chamber 2060. With thisapparatus, the mixed fluid from which part of the mist has beencollected in the previous-stage collection chamber 2060 is supplied tothe air separator 2050. However, with the separation apparatus, any oneof a cyclone, a punched plate, a demistor, a chevron, a scrubber, aspray tower, and an electrostatic collector can be connected between theair separator and the collection chamber to collect the mist, though notillustrated in the drawings.

The air separated by the air separator 50, 2050, 3050, 4050 is an airthat does not contain the target substance. With the apparatus of FIG.1, the air separated by the air separator 50 is supplied to theatomization chamber 4. With the apparatus in which the air separated bythe air separator 50 is supplied to the atomization chamber 4, the mistcan be produced efficiently by atomization in the atomization chamber 4.The reason is that the air separated from the mixed fluid by the airseparator 50 does not contain the target substance. Also, since the airseparated by the air separator 50 is air that is controlled to have anoptimum temperature for producing the mist in the atomization chamber 4,the mist can be efficiently produced by supplying this air into theatomization chamber 4.

The mixed fluid from which air has been separated by the air separator50, 2050, 3050, 4050 has a smaller content of air, namely, has a largercontent of the mist relative to air, so that the target substance of themist will be in a supersaturated state. Therefore, the mist can becollected efficiently in the collection chamber 5, 205, 305, 405. Sinceair is separated from the mixed fluid by the air separator 50, 2050,3050, 4050, the mixed fluid supplied to the collection chamber 5, 205,305, 405 has a smaller content of air than the mixed fluid dischargedfrom the atomization chamber 4, 204, 304, 404.

The mixed fluid from which part of the air has been separated by the airseparator 50, 2050, 3050, 4050 is transported to the collection chamber5, 205, 305, 405. The mixed fluid is supplied to the collection chamber5, 205, 305, 405 by a forced transporter 35, 2035, 3035, 4035 made of ablower or a compressor. The forced transporter 35, 2035, 3035, 4035 isconnected between the air separator 50, 2050, 3050, 4050 and thecollection chamber 5, 205, 305, 405 so as to supply the mixed fluid fromthe air separator 50, 2050, 3050, 4050 to the collection chamber 5, 205,305, 405. The forced transporter 35, 2035, 3035, 4035 absorbs the mixedfluid from which part of the air has been separated by the air separator50, 2050, 3050, 4050, and supplies the absorbed mixed fluid to thecollection chamber 5, 205, 305, 405.

With the apparatus shown in FIGS. 3 and 4, a compressor 3035A, 4035A isused as the forced transporter 3035, 4035. When the compressor 3035A,4035A is used as the forced transporter 3035, 4035, the mixed fluid canbe supplied to the collection chamber 305, 405 by being pressurized tohave a pressure higher than an atmospheric pressure. With thisseparation apparatus, in the collection chamber 305, 405, the saturationvapor partial pressure of the target substance in gas phase is madelower than the saturation vapor partial pressure thereof underatmospheric pressure, whereby the mist can be aggregated and collectedmore effectively.

The compressor 3035A, 4035A to be used may be a compressor of a pistontype, a compressor of a rotary type, a compressor of a diaphragm type, acompressor of a Rischorm type, or the like. The compressor 3035A, 4035Ato be used is preferably of a type that can transport the mixed fluid bypressurizing the mixed fluid to 0.2 to 1 MPa.

With the apparatus that increases the pressure in the collection chamber305, 405 by using the compressor 3035A, 4035A as the forced transporter3035, 4035, a throttle valve 3036, 4036 is connected to an outlet sideof the collection chamber 305, 405. However, if the flow rate of themixed fluid supplied to the collection chamber by the compressor ishigh, the throttle valve need not always be provided on the outlet sideof the collection chamber. The reason is that, if the passage resistanceon the outlet side of the collection chamber is large, the compressorcan supply a large amount of the mixed fluid to the collection chamberto increase the pressure in the collection chamber to be higher than anatmospheric pressure. However, when the throttle valve is connected tothe outlet side of the collection chamber, the pressure in thecollection chamber can be efficiently increased to be higher than anatmospheric pressure. The throttle valve 3036, 4036 increases thepressure in the collection chamber 305, 405 by increasing the passageresistance of the mixed fluid discharged from the collection chamber305, 405. The throttle valve 3036, 4036 to be used may be a valve thatcan adjust the passage resistance of the mixed fluid by adjusting thedegree of opening, a pipe made of a narrow pipe such as a capillary tubeto increase the passage resistance of the mixed fluid, or a pipe filledwith a resisting material that increases the passage resistance of themixed fluid, or the like. According as the throttle valve 3036, 4036makes the passage resistance larger, the pressure in the collectionchamber 305, 405 will be higher.

FIG. 14 shows a state in which the amount of ethanol of the targetsubstance contained in air, which is a mixed fluid, decreases as thepressure in the collection chamber is increased so as to be higher thanan atmospheric pressure. As will be understood from this graph, the airof the mixed fluid can contain a larger amount of ethanol in a gas stateas the temperature becomes higher. However, when the pressure becomeshigher, the amount of ethanol that can be contained in a gas staterapidly decreases. For example, at a temperature of 30° C., the amountof ethanol that can be contained in dry air considerably decreases toabout ⅕ when the pressure is raised from 0.1 MPa, which is anatmospheric pressure, to 0.5 MPa. When the maximum amount of ethanolthat can be contained in a gas state decreases, a larger amount ofethanol than the maximum amount of ethanol will all be in a state of asupersaturated mist, and can be efficiently collected. The ethanolcontained in a gas state cannot be aggregated and collected unlessturned into a mist. Also, even if ultrasonic oscillation atomizes thetarget substance into a mist state, the target substance cannot beaggregated and collected if the mist vaporizes into a gas state. Forthis reason, it is important to collect the target substance, which hasbeen turned into a mist by ultrasonic oscillation, in a mist statewithout vaporizing the mist. Also, even if the mist vaporizes, the mistcan be liquefied again in a supersaturated state and collected. Namely,in order to collect the target substance efficiently, it is importantthat the target substance once turned into a mist is vaporized into themixed fluid in an amount as little as possible. The present inventionincreases the pressure of the mixed fluid containing the mist to behigher than an atmospheric pressure to reduce the saturation vaporpartial pressure of the target substance, thereby efficiently collectingthe target substance contained in the mixed fluid not in a gas state butin a mist state. The saturation vapor partial pressure can be reduced bycooling the mixed fluid; however, the pressuring method has acharacteristic such that the compressor can lower the saturation vaporpartial pressure efficiently and extremely easily with low energyconsumption. Further, pressurizing while cooling can further reduce thesaturation vapor partial pressure of the target substance, whereby thetarget substance can be collected more efficiently.

When the compressor 3035A, 4035A compresses the mixed fluid, the mixedfluid undergoes adiabatic compression to generate heat. Also, when themixed fluid passes through the throttle valve 3036, 4036, the mixedfluid undergoes adiabatic expansion to be cooled. The mixed fluidsupplied from the compressor 3035A, 4035A to the collection chamber 305,405 is preferably cooled so as to collect the mist efficiently.Therefore, when heat is generated, the collection efficiency will bepoor. In order to reduce this problem, the apparatus shown in FIG. 3 isprovided with a heat-discharging heat exchanger 3037 for exchanging heatbetween a portion on an outlet side of the throttle valve 3036 and aportion on an outlet side of the compressor 3035A and on an inlet sideof the collection chamber 305. With the mixed fluid cooled by adiabaticexpansion on the outlet side of the throttle valve 3036, theheat-discharging heat exchanger 3037 cools the mixed fluid heatedthrough adiabatic compression by the compressor 3035A.

The heat-discharging heat exchanger 3037 circulates a refrigerant in theinside of a circulation pipe 3038. One end of the circulation pipe 3038is thermally coupled to the outlet side of the throttle valve 3036, andthe other end of the circulation pipe 3038 is thermally coupled to theoutlet side of the compressor 3035A. The refrigerant that circulates inthe circulation pipe 3038 is cooled on the outlet side of the throttlevalve 3036. The refrigerant cooled here cools the outlet side of thecompressor 3035A. Though not illustrated in the drawings, the part ofthe circulation pipe 3038 that is thermally coupled has a double-pipestructure so as to achieve thermal coupling between the mixed fluid andthe refrigerant.

Further, the apparatus shown in FIG. 3 is provided with a secondheat-discharging heat exchanger 3039 that connects the outlet side ofthe throttle valve 3036 to a condenser 3040 that cools the cooling heatexchanger 3033. This second heat-discharging heat exchanger 3039 has thesame structure as the aforesaid heat-discharging heat exchanger 3037,and cools the refrigerant on the outlet side of the throttle valve 3036.The cooled refrigerant cools the condenser 3040 to liquefy therefrigerant that circulates in the inside of the condenser 3040.

With the apparatus shown in FIGS. 2 to 4, the atomization chamber 204,304, 404, the air separator 2050, 3050, 4050, and the collection chamber205, 305, 405 are connected with a circulation duct 2030, 3030, 4030 soas to circulate the mixed fluid through the atomization chamber 204,304, 404 and the collection chamber 205, 305, 405. With the apparatus ofFIG. 1, the outlet side of the atomization chamber 4, the air separator50, and the inlet side of the collection chamber 5 are connected withthe circulation duct 30; however, the outlet side of the collectionchamber 5 and the inlet side of the atomization chamber 4 are notconnected with a circulation duct. With this apparatus, the airseparated by the air separator 50 is circulated into the atomizationchamber 4.

The collection chamber 5, 205, 305, 405 shown in FIGS. 1 to 4incorporates a cooling heat exchanger 33, 2033, 3033, 4033 for coolingand aggregating the mist. In the cooling heat exchanger 33, 2033, 3033,4033, a fin (not illustrated) is fixed to the heat exchange pipe 34,2034, 3034, 4034. By circulating a refrigerant for cooling or coolingwater in the heat exchange pipe 34, 2034, 3034, 4034, the cooling heatexchanger 33, 2033, 3033, 4033 is cooled. Part of the mist atomized inthe atomization chamber 4, 204, 304, 404 is vaporized into gas. The gasis cooled by the cooling heat exchanger 33, 2033, 3033, 4033 of thecollection chamber 5, 205, 305, 405 and is condensed and aggregated tobe collected. The mist that flows into the collection chamber 5, 205,305, 405 collides with the cooling heat exchanger 33, 2033, 3033, 4033,or collides with each other to form a large aggregation, or collideswith the fin or the like of the cooling heat exchanger 33, 2033, 3033,4033 to form a large aggregation to be collected as a solution. The airfrom which the mist and the gas are aggregated and collected by thecooling heat exchanger 33, 2033, 3033, 4033 is circulated again to theatomization chamber 4, 204, 304, 404 via the circulation duct 30, 2030,3030, 4030.

In order to collect the mist more speedily in the collection chamber,the collection chamber 155 in FIG. 15 is provided with nozzles 156 thatscatter the solution. The nozzles 156 are connected to the bottomportion of the collection chamber 155 via a circulation pump 1515. Thecirculation pump 1515 sucks the solution collected in the collectionchamber 155 and sprays the sucked solution through the nozzles 156.

With the separation apparatus shown in FIG. 15, the nozzles 156 aredisposed in the upper part of the collection chamber 155. The nozzles156 in the upper part spray the solution downwards. The solution sprayedthrough the nozzles 156 is made of water droplets that are sufficientlylarger than the droplets of the mist atomized by the atomizer, and falldown speedily in the inside of the collection chamber 155. When fallingdown, the water droplets collide with the mist that is floating in theinside of the collection chamber 155, and fall down while collecting themist. Therefore, the mist floating in the collection chamber 155 can becollected speedily and efficiently.

With the separation apparatus shown in FIG. 15, the nozzles 156 aredisposed in the upper part; however, the nozzles can be disposed in thelower part of the collection chamber. The nozzles in the lower partspray the solution upwards. These nozzles spray the solution at a speedthat makes the solution collide with the ceiling of the collectionchamber or at a speed that lifts the solution up to a neighborhood ofthe ceiling. The solution that is sprayed to be lifted up to theneighborhood of the ceiling changes its direction downwards at theneighborhood of the ceiling and falls. Therefore, the sprayed solutiongets in contact with the mist when rising and falling, therebyefficiently collecting the mist.

Plural sheets of baffle plates 167 are provided in the inside of thecollection chamber 165 of FIG. 16. Each baffle plate 167 is spaced apartfrom adjacent baffle plates 167 with a gap through which the mist canpass, and is disposed in a vertical posture. The mist collides with thesurface of the baffle plates 167 to produce a solution, and the verticalbaffle plates 167 can let the adhering solution flow down in a naturalmanner to be collected. The baffle plates 167 in FIG. 16 have an unevensurface, whereby the mist comes into contact more efficiently with thesurface to be collected.

Furthermore, a fan 169, which blows and stirs the mist in a forcedmanner, is provided in the collection chamber 165 of FIG. 16. The fan169 stirs the mist in the collection chamber 165. The droplets of thestirred mist collide with each other and aggregate, or collide with thesurface of the baffle plates 167 and aggregate. The aggregated mistquickly falls down and is collected. The fan 169 in FIG. 16 blows themist of the collection chamber 165 downwards for circulation.

Furthermore, a mist oscillator 178 for oscillating the mist to increasethe probability of collision with each other is provided in thecollection chamber 175 of FIG. 17. The mist oscillator 178 includes anelectrical-to-mechanical oscillation converter, which oscillates the gasof the collection chamber 175, and an oscillation power supply thatdrives the electrical-to-mechanical oscillation converter. Theelectrical-to-mechanical oscillation converter is a speaker for emittinga sound at an audible frequency, an ultrasonic oscillator for emittingultrasonic waves having a frequency higher than an audible frequency, orthe like. In order that the electrical-to-mechanical oscillationconverter may efficiently oscillate the mist, the oscillation emittedfrom the electrical-to-mechanical oscillation converter is resonated inthe collection chamber 175. In order to achieve this resonation, theelectrical-to-mechanical oscillation converter oscillates the mist atthe frequency that resonates in the collection chamber 175. In otherwords, the collection chamber 175 is designed to have a shape that isresonated with the oscillation emitted from the electrical-to-mechanicaloscillation converter.

Ultrasonic waves involve high frequencies above the audible frequency ofhuman beings and are inaudible to the human ear. For this reason, withthe mist oscillator 178 emitting ultrasonic waves, even if the gas inthe collection chamber 175 is intensely oscillated, in other words, evenif the output power of the electrical-to-mechanical oscillationconverter is very high, the mist oscillator will not harm human beingsdue to sound. Therefore, ultrasonic waves have an advantage in that themist can be intensely oscillated, and the droplets of the mist are madeto collide with each other efficiently to be quickly collected.

With the separation apparatus described above, a device that aggregatesthe mist efficiently is disposed in the collection chamber, so that themist can be aggregated more speedily to prepare a solution having a highconcentration. Further, though not illustrated, the separation apparatusof the present invention may incorporate in the collection chamber allof the nozzles that spray the solution, the fan that stirs the mist, andthe oscillator that oscillates the mist to aggregate the mist mostefficiently. Also, two devices that aggregate the mist may beincorporated to aggregate the mist efficiently.

The atomization chamber 4, 204, 304, 404 and the collection chamber 5,205, 305, 405 are preferably filled with an inert gas. With thisapparatus, the inert gas prevents deterioration of the quality of thesolution in the atomization chamber 4, 204, 304, 404 and the collectionchamber 5, 205, 305, 405. For this reason, a solution having a highconcentration can be obtained in a state having a higher productquality.

As this invention may be embodied in several forms without departingfrom the spirit or essential characteristics thereof, the presentembodiment is therefore illustrative and not restrictive, since thescope of the invention is defined by the appended claims rather than bythe description preceding them, and all changes that fall within themetes and bounds of the claims, or equivalence of such metes and boundsthereof are therefore intended to be embraced by the claims. Thisapplication is based on applications No. 2004-097781 filed in Japan onMar. 30, 2004, and No. 11/091,486 filed in U.S. on Mar. 29, 2005, thecontent of which is incorporated hereinto by reference.

1. A method of separating a solution, the method comprising: atomizing asolution containing a target substance into a mist in an atomizer toproduce a mixed fluid of mist and gas; separating gas from the mixedfluid by bringing the mixed fluid into contact with a primary surface ofa gas transmission membrane contained in a gas separator, wherein thegas transmission membrane has pores sized to transmit gas but not thetarget substance contained in the mist, wherein a pressure on theprimary surface of the gas transmission membrane is made higher than apressure on a secondary surface of an opposite side of the gastransmission membrane so that the gas in the mixed fluid passes throughthe gas transmission membrane to separate part or all of the gascontained in the mixed fluid; and collecting the mist from the mixedfluid from which at least part of the gas has been separated by the gastransmission membrane, wherein the mist is collected by aggregating andcollecting the mist in a collection chamber connected to an outlet sideof a primary passage way provided in the gas separator, wherein the mistis aggregated and collected by cooling the mixed fluid with a coolingheat exchanger provided in the collection chamber, and wherein the gascontains at least one of hydrogen and helium.
 2. The method ofseparating a solution according to claim 1, wherein the atomizeratomizes the solution into the mist by ultrasonic oscillation.
 3. Themethod of separating a solution according to claim 2, wherein theatomizer atomizes the solution into the mist by ultrasonic oscillationat a frequency of 1 MHz or higher.
 4. The method of separating asolution according to claim 1, wherein the mixed fluid, from which themist has been separated by cooling and aggregation after part of the gasis separated by the gas transmission membrane, is circulated andsupplied to the atomizer.
 5. The method of separating a solutionaccording to claim 1, wherein the gas separated from the mixed fluid bythe gas transmission membrane is supplied to the atomizer.
 6. The methodof separating a solution according to claim 1, wherein the solutioncontaining the target substance is any one of refined sake, beer, wine,vinegar, mirin (sweet sake for cooking), spirits, shochu (Japanesespirits), brandy, whisky, and liqueur.
 7. The method of separating asolution according to claim 1, wherein the solution containing thetarget substance is a solution containing a perfume, an aromaticcomponent, or a fragrant component.
 8. The method of separating asolution according to claim 1, wherein the solution containing thetarget substance is a solution containing an organic compound that isclassified as any one of alkane and cycloalkane, which are a saturatedhydrocarbon, alkene, cycloalkene, and alkyne, which are an unsaturatedhydrocarbon, ether, thioether, and aromatic hydrocarbon, or a compoundobtained by bonding these.
 9. The method of separating a solutionaccording to claim 1, wherein the solution containing the targetsubstance is a solution containing a substance obtained by substitutinga halogen(s) for at least one hydrogen atom or functional group of anorganic compound that is classified as any one of alkane andcycloalkane, which are a saturated hydrocarbon, alkene, cycloalkene andalkyne, which are an unsaturated hydrocarbon, ether, thioether, andaromatic hydrocarbon, or a bonded compound of these.
 10. The method ofseparating a solution according to claim 1, wherein the solutioncontaining the target substance is a solution containing a substanceobtained by substituting a hydroxy group(s) for at least one hydrogenatom or functional group of an organic compound that is classified asany one of alkane and cycloalkane, which are a saturated hydrocarbon,alkene, cycloalkene and alkyne, which are an unsaturated hydrocarbon,ether, thioether, and aromatic hydrocarbon, or a bonded compound ofthese.
 11. The method of separating a solution according to claim 1,wherein the solution containing the target substance is a solutioncontaining a substance obtained by substituting an amino group(s) for atleast one hydrogen atom or functional group of an organic compound thatis classified as any one of alkane and cycloalkane, which are asaturated hydrocarbon, alkene, cycloalkene and alkyne, which are anunsaturated hydrocarbon, ether, thioether, and aromatic hydrocarbon, ora bonded compound of these.
 12. The method of separating a solutionaccording to claim 1, wherein the solution containing the targetsubstance is a solution containing a substance obtained by substitutinga carbonyl group(s) for at least one hydrogen atom or functional groupof an organic compound that is classified as any one of alkane andcycloalkane, which are a saturated hydrocarbon, alkene, cycloalkene andalkyne, which are an unsaturated hydrocarbon, ether, thioether, andaromatic hydrocarbon, or a bonded compound of these.
 13. The method ofseparating a solution according to claim 1, wherein the solutioncontaining the target substance is a solution containing a substanceobtained by substituting a carboxyl group(s) for at least one hydrogenatom or functional group of an organic compound that is classified asany one of alkane and cycloalkane, which are a saturated hydrocarbon,alkene, cycloalkene and alkyne, which are an unsaturated hydrocarbon,ether, thioether, and aromatic hydrocarbon, or a bonded compound ofthese.
 14. The method of separating a solution according to claim 1,wherein the solution containing the target substance is a solutioncontaining a substance obtained by substituting a nitro group(s) for atleast one hydrogen atom or functional group of an organic compound thatis classified as any one of alkane and cycloalkane, which are asaturated hydrocarbon, alkene, cycloalkene and alkyne, which are anunsaturated hydrocarbon, ether, thioether, and aromatic hydrocarbon, ora bonded compound of these.
 15. The method of separating a solutionaccording to claim 1, wherein the solution containing the targetsubstance is a solution containing a substance obtained by substitutinga cyano group(s) for at least one hydrogen atom or functional group ofan organic compound that is classified as any one of alkane andcycloalkane, which are a saturated hydrocarbon, alkene, cycloalkene andalkyne, which are an unsaturated hydrocarbon, ether, thioether, andaromatic hydrocarbon, or a bonded compound of these.
 16. The method ofseparating a solution according to claim 1, wherein the solutioncontaining the target substance is a solution containing a substanceobtained by substituting a mercapto group(s) for at least one hydrogenatom or functional group of an organic compound that is classified asany one of alkane and cycloalkane, which are a saturated hydrocarbon,alkene, cycloalkene and alkyne, which are an unsaturated hydrocarbon,ether, thioether, and aromatic hydrocarbon, or a bonded compound ofthese.
 17. An apparatus for separating a solution, the apparatuscomprising: an atomization chamber for receiving a solution containing atarget substance; an atomizer for scattering the solution in theatomization chamber into gas as a mist to produce a mixed fluid of gasand the mist of the solution; and a gas separator, connected to theatomization chamber, for separating gas from the mixed fluid, the gasseparator having an interior that is partitioned by a gas transmissionmembrane to provide a primary passageway for passing the mixed fluid anda secondary gas-discharge passageway for discharging gas, the gasseparator having a pore size that allows transmission of gas but nottransmission of the target substance; and a forced gas dischargerconnected to the secondary gas discharge passageway of the gasseparator, the forced gas discharger being operable to discharge the gasin the secondary gas-discharge passageway in a forced manner to make apressure on a primary surface of the gas transmission membrane higherthan a pressure on a secondary surface of the gas transmission membraneso that the gas contained in the mixed fluid may be transmitted throughthe gas transmission membrane to separate gas from the mixed fluid thatpasses through the primary passageway; a collection chamber connected toan outlet side of the primary passageway provided in the gas separator;and a cooling heat exchanger provided in the collection chamber, whereinthe mist from the mixed fluid can be aggregated and collected by coolingthe mixed fluid with the cooling heat exchanger, wherein the gascontains one of hydrogen and helium.
 18. The apparatus for separating asolution according to claim 17, wherein the gas transmission membraneincludes a filter member obtained by coating a surface of a ceramic withzeolite.
 19. The apparatus for separating a solution according to claim17, wherein the atomizer includes an ultrasonic oscillator for atomizingthe solution into a mist by ultrasonic oscillation and an ultrasonicpower supply connected to the ultrasonic oscillator to supplyhigh-frequency electric power to the ultrasonic oscillator forultrasonic oscillation.
 20. The apparatus for separating a solutionaccording to claim 17, wherein the mist is collected by connecting anyone of a cyclone, a punched plate, a demistor, a chevron, a scrubber, aspray tower, and an electrostatic collector to an outlet side or aninlet side of the gas separator.
 21. The apparatus for separating asolution according to claim 17, wherein a collection chamber isconnected to the atomization chamber, whereby the gas from which gas hasbeen separated by the gas separator and further the mist has beenseparated in the collection chamber is supplied to the atomizationchamber.
 22. The apparatus for separating a solution according to claim17, wherein the secondary gas-discharging passageway of the gasseparator is connected to the atomization chamber, whereby the gasseparated from the mixed fluid by the gas transmission membrane of thegas separator is supplied to the atomization chamber.